Hi guys.
I've finally got around to working on that board!
I know that star grounding is a good idea, but is it critical in this application? I am trying to do a board layout which will enable C1 100nF to be a Mundorf Supreme or some other nice polypropylene cap. This is large though, and making things tricky to work around.
Cheers, Lee.
I've finally got around to working on that board!
I know that star grounding is a good idea, but is it critical in this application? I am trying to do a board layout which will enable C1 100nF to be a Mundorf Supreme or some other nice polypropylene cap. This is large though, and making things tricky to work around.
Cheers, Lee.
Thomo said:
Me I have used a U shaped peripheral copper wire busbar with the arm and RCAs grounded at its one end, and I have no ground loops at all. Star is theoretically better though.
The Supreme is the biggest one, its good to allow space, but if its really tricky, just make space for chunky radial ones or smaller axial like the Auricap. I use a Soviet radial Polystyrene that is very neutral and big enough but no monster.
Attachments
LOL. Oh yeah.
I was thinking of keeping the psu either on a separate board, or in a separate case.
I could add the regulator Salas posted, but I don't have the time to test if it works before implementing into the layout.
I have just double-checked my layout against the schematic and everything seems in order. (I think the fets are the correct way round, lol).
Regards, Lee.
I was thinking of keeping the psu either on a separate board, or in a separate case.
I could add the regulator Salas posted, but I don't have the time to test if it works before implementing into the layout.
I have just double-checked my layout against the schematic and everything seems in order. (I think the fets are the correct way round, lol).
Regards, Lee.
Thomo said:
Hi Lee
Wonderfull work.!
Can I use your layout for the schematic Salas designed for my benz ACE 0.8mv output ?
After some surprises related with my meridian 101 (I found it has opamps instead of DIS
), I am convinced I need to replace the preamp.... I will need your help to build a simple one including Salas RIAA.This is becoming a feast.
Ricardo
RCruz said:
Hi Lee
Wonderfull work.!
Can I use your layout for the schematic Salas designed for my benz ACE 0.8mv output ?
After some surprises related with my meridian 101 (I found it has opamps instead of DIS
This is becoming a feast.
Ricardo
Your 46dB schematic is already playing with a Benz Ace Clear medium output on a Pink Triangle with Origin Live DC motor (battery) mod. A friend of mine who lives on a Greek island made it and uses it there. He called several times to tell how his Benz plays 2 times better now. He has used very highly regarded commercial transistor or tube phono stages and step ups before. He will not retip his VDH cart now, because the Benz highs bettered it with this phono now he says, and he will save EUR 750!. So, I don't think that you will have any fidelity deficiencies with Benz Clear + Salas regarding your 101 competition. Since my friend reported that the gain I chose works very correctly with the Benz Clear, do you want me to calculate Lee's version for 46dB so you can make it on his PCB, only changing a few values and the B+ voltage?
Thomo said:
Nice work Lee. Better keep PSU option separate, correct. Whatever wins for taste or availability, better not be carved in stone. The PSU will lend a lot of its character to such a circuit and we better be flexible here. Here is the 2SK170 pin designation for your final check.
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Since Lee has taken the hassle and prepared a PCB, I think that a 52dB MC version based on the particular PCB schematic is in order. This one has gain centered for 0.5mV MC and can cater for the majority of normal MC carts. This one has all. Cascode, common source, buffer, local current sourced shunt PSU for cascode. Its an all rounder. Now both the MM and MC people have a common version and a common PCB. In such a way we make things more DIY ready.
Only thing still in question is if we have a really good shunt PSU design that adds a lot of performance to my RIAA, or an oscillating, noisy, blown mess... Cygnus X will soon tell!
Only thing still in question is if we have a really good shunt PSU design that adds a lot of performance to my RIAA, or an oscillating, noisy, blown mess...
Cygnus X will soon tell!Attachments
salas said:
Hi Salas
That would be "gold over blue".
Somehow I keep finding exceptional people in diyaudio always willing to help in the most difficult and critical areas.
By all means do post a Benz ACE Clear version !
I have recently found that the RIAA is indeed a critical point. I opened my 101 and found the discrete MM stage I have been listening to for 30 years now. Some time ago I purchased a MC module that I finally tried last weekend
(This MC version is based on a opamp RIAA... the sound looses all the stereo imagery, instruments are projected forward and loose detail and attack).I know this Benz has potential (wonderfull stylus). I have been listening to a VDH with a Naim MC pre + big Naim PSU and the timbre is quite identical. With a good RIAA it might outrun the VDH.
So I believe a jfet class A zero feedback passive RIAA might elevate things a lot. (I always loved the coherent sound of tubes but since I built this jfet output stage for the CDP, I believe these are like solid state valves)
Thank you for all the support and trouble.
Ricardo
